History of CR 306.6

Every distinct wording since 2010, newest first.

May 3, 2019 · War of the Spark

Planeswalkers can be attacked. (See rule 508, “Declare Attackers Step.”)

January 25, 2019 · Ravnica Allegiance

Planeswalkers can be attacked. (See rule 508, "Declare Attackers Step.")

May 1, 2014 · Journey into Nyx

Planeswalkers can be attacked. (See rule 508, “Declare Attackers Step.”)

September 30, 2011 · Innistrad

Planeswalkers can be attacked. (See rule 508, "Declare Attackers Step.")

June 17, 2011 · Commander 2011

Planeswalkers can be attacked. (See rule 508, “Declare Attackers Step.”)

April 1, 2011 · Duel Decks: Knights vs. Dragons

Planeswalkers can be attacked. (See rule 508, "Declare Attackers Step.")

October 1, 2010 · Scars of Mirrodin

Planeswalkers can be attacked. (See rule 508, “Declare Attackers Step.”)

February 1, 2010 · Worldwake

Planeswalkers can be attacked. (See rule 508, "Declare Attackers Step.")